Set the default Blend Type
You could get a script writer to make a add strip effect option. The Transform Addon currently creates a transform strip upon key press. So it is possible.

Currently over at the BA forum, user "snu" is actively developing a VSE script that might add this function for you. http://blenderartists.org/forum/showthread.php?338598-Addon-WIP-VSE-Quick-functions-Snaps-Fades-Zoom-Parenting-Titling-Play-speed